The collaboration between the pair means that from now, when someone searches for a restaurant or movie on Bing, they can see what their friends have liked. It's now easier for people to get online guidance from their friends, Microsoft said.
"It's an unfolding of a new era of search," said Qi Lu, president of Microsoft's online services division. "Our quest is to enable our users to make informed decisions faster."
The social search announcement is an extension of an ongoing partnership between Microsoft and Facebook. Lu said the feature isn't the final act of the relationship, and to expect more tools and technologies in the future.
Facebook's search, which is powered by Bing, is also making it easier to find people on the social networking site.
"Now when you search on Bing, rather than showing you all the Matthew Kims out there, Bing finds and provides the results most relevant to you based on your Facebook connections - those with whom you have mutual friends will now show up first," said Facebook CEO and co-founder Mark Zuckerberg. "Bing is also making more prominent the ability to add these people as friends on Facebook directly from Bing."
Ezra Gottheil, an analyst at Technology Business Research, said teaming up is a good idea for Facebook and for Microsoft.
"It has appeal to Facebook's core audience, people who care about what their friends like," Gottheil said. "I think it will increase Bing traffic, and drive some revenue to Facebook."
See also: Facebook rolls out temporary passwords